AMS Climate Science and Climatology 3

Question 1

Atmospheric CO2 concentrations have surpassed approximately what level in recent years (mid-2020s)?

Accepted Answer

420 ppm

Answer

Atmospheric CO2 concentration has exceeded 420 ppm in the 2020s, compared to the pre-industrial level of approximately 280 ppm, representing a ~50% increase driven by fossil fuel combustion and land-use change.

Question 2

Which climate feedback amplifies warming by reducing the extent of highly reflective surfaces at high latitudes?

Accepted Answer

Ice-albedo feedback

Answer

As temperatures rise, ice and snow melt, exposing darker ocean and land surfaces with lower albedo, which absorb more solar radiation and further amplify the initial warming in a positive feedback loop.

Question 3

The Planck feedback in the climate system is classified as:

Accepted Answer

A fundamental negative feedback that stabilizes climate

Answer

The Planck (blackbody) feedback is a stabilizing negative feedback: as surface temperature increases, the planet emits more longwave radiation to space, acting as a restoring force against further warming.

Question 4

Equilibrium Climate Sensitivity (ECS) is defined as the equilibrium global mean surface temperature change resulting from:

Accepted Answer

A doubling of atmospheric CO2 concentration

Answer

ECS is the long-term global mean surface temperature increase after the climate system reaches a new equilibrium following a doubling of atmospheric CO2, with the IPCC AR6 likely range of 2.5–4.0°C.

Question 5

The current rise in global mean sea level is primarily attributed to:

Accepted Answer

Thermal expansion of seawater and mass loss from glaciers and ice sheets

Answer

Current sea level rise is driven roughly equally by thermal expansion of warming ocean water and by mass contributions from melting mountain glaciers and the Greenland and Antarctic ice sheets.

American Meteorological Society Certification Practice Test

American Meteorological Society Certification Practice Test

AMS Climate Science and Climatology 3